MOTS-c + SS-31 is a two-compound mitochondrial research combination consisting of MOTS-c, a mitochondrially encoded peptide associated with metabolic and cellular stress signaling, and SS-31 (elamipretide), a synthetic mitochondria-targeted tetrapeptide that interacts with cardiolipin at the inner mitochondrial membrane. The combination is discussed in research and commercial research-material contexts, but it is not a standardized clinical formulation and should not be described as a clinically validated combination protocol.
MOTS-c + SS-31 refers to a research combination of two biologically distinct mitochondrial peptides. MOTS-c is a 16-amino-acid peptide encoded by mitochondrial DNA and investigated primarily as a signaling molecule involved in metabolic and cellular stress pathways. SS-31, also known as elamipretide or MTP-131, is a synthetic mitochondria-targeted tetrapeptide that localizes to the inner mitochondrial membrane and interacts with cardiolipin.
Although both compounds are frequently grouped under the broad "mitochondrial peptide" category, that shared category does not mean they have the same mechanism, pharmacology, clinical evidence, or regulatory status.
The two components should be evaluated independently before making any claim about the combination.
MOTS-c is a mitochondrial-derived peptide encoded by a small open reading frame within mitochondrial 12S rRNA. Research has investigated its relationship with metabolic regulation, exercise responses, cellular stress signaling and mitochondrial biology.
Human literature includes observational measurements of endogenous MOTS-c. A Phase 2a study registered in 2026 is evaluating administered MOTS-c in adults with prediabetes and overweight/obesity.
SS-31 is the research name commonly associated with elamipretide, a mitochondria-targeted peptide that interacts with cardiolipin in the inner mitochondrial membrane.
Unlike MOTS-c, elamipretide has undergone multiple human clinical trials. Its evidence should nevertheless be interpreted by indication and endpoint rather than generalized to every proposed mitochondrial application.
MOTS-c has a growing research literature, but the evidence must be divided into endogenous human observations, preclinical experiments and interventional human research.
MOTS-c was described as a mitochondrial-derived peptide associated with metabolic regulation and cellular signaling.
Human studies have measured endogenous circulating MOTS-c in relation to exercise, metabolic conditions and other physiological states. These studies do not establish the effects of administering pharmaceutical MOTS-c.
A Phase 2a registered study is investigating MOTS-c administration in adults with prediabetes and overweight/obesity. Results should be distinguished from observational MOTS-c studies.
SS-31 has a substantially more developed human clinical evidence base than MOTS-c. Trials have evaluated elamipretide in mitochondrial myopathy, heart failure, Barth syndrome and other mitochondrial-related settings.
An early randomized dose-escalation study evaluated elamipretide in adults with genetically confirmed primary mitochondrial myopathy.
The large randomized MMPOWER-3 trial evaluated 24 weeks of subcutaneous elamipretide in primary mitochondrial myopathy. It did not meet its primary endpoints for 6-minute walk distance or total fatigue.
In 2025, the FDA granted accelerated approval to Forzinity (elamipretide) for improving muscle strength in eligible patients with Barth syndrome.
Published research on MOTS-c and published clinical research on SS-31/elamipretide should not be combined into a claim that the two-compound stack has demonstrated efficacy or safety.
The fact that both compounds are described as mitochondrial peptides does not establish pharmacological synergy, additive efficacy, compatibility, optimal ratio, or a shared clinical indication.
| Evidence category | MOTS-c | SS-31 / Elamipretide | MOTS-c + SS-31 |
|---|---|---|---|
| Mechanistic research | Yes | Yes | Combination mechanism not established |
| Human observational research | Yes | Yes / extensive clinical development | Not equivalent to combination evidence |
| Human interventional research | Emerging / investigational | Yes | No controlled combination study identified |
| Combination efficacy evidence | Not established | ||
| Combination safety evidence | Not established | ||
There is no universally standardized MOTS-c + SS-31 formulation. Research-material suppliers may offer the compounds as separate vials, bundled research sets, or co-formulated products. Label composition, total mass, ratio and physical presentation can therefore vary.
| Format | MOTS-c | SS-31 | Standardized? | Interpretation |
|---|---|---|---|---|
| Separate-vial research bundle | Individual vial | Individual vial | No universal standard | Each component can be documented independently. |
| Co-formulated vial | Label-specific mass | Label-specific mass | No | Every component must be calculated separately. |
| Custom laboratory formulation | Protocol-specific | Protocol-specific | No universal standard | Composition must come from the specific study or label. |
For a multi-component vial, the final liquid volume is shared by both compounds, but the mass of each compound remains separate. Therefore, concentration must be calculated independently for MOTS-c and SS-31.
Component concentration (mg/mL) = component mass (mg) ÷ final liquid volume (mL)| Final liquid volume | MOTS-c mass | MOTS-c concentration | SS-31 mass | SS-31 concentration | Total mass |
|---|---|---|---|---|---|
| 1 mL | 5 mg | 5 mg/mL | 5 mg | 5 mg/mL | 10 mg |
| 2 mL | 5 mg | 2.5 mg/mL | 5 mg | 2.5 mg/mL | 10 mg |
| 3 mL | 5 mg | 1.667 mg/mL | 5 mg | 1.667 mg/mL | 10 mg |
| 5 mL | 5 mg | 1 mg/mL | 5 mg | 1 mg/mL | 10 mg |
| 10 mL | 5 mg | 0.5 mg/mL | 5 mg | 0.5 mg/mL | 10 mg |
In the hypothetical 5 mg + 5 mg example, the vial contains 10 mg of total peptide material. However, at 5 mL final volume the correct component concentrations are:
| Component | Mass | Final volume | Correct concentration |
|---|---|---|---|
| MOTS-c | 5 mg | 5 mL | 1 mg/mL |
| SS-31 | 5 mg | 5 mL | 1 mg/mL |
| Total peptide mass | 10 mg | 5 mL | Do not label this as the concentration of either component. |
This simple calculator performs concentration mathematics independently for MOTS-c and SS-31. It does not provide dosing, administration, frequency or treatment recommendations.
Increasing the final liquid volume decreases the concentration of both components because the same fixed mass is distributed through a larger volume. Decreasing the final volume increases the concentration of each component.
| Final volume | 5 mg MOTS-c | 5 mg SS-31 | Relationship |
|---|---|---|---|
| 1 mL | 5 mg/mL | 5 mg/mL | Highest concentration in this example |
| 2 mL | 2.5 mg/mL | 2.5 mg/mL | Half the 1 mL concentration |
| 3 mL | 1.667 mg/mL | 1.667 mg/mL | One-third of the original mass per mL |
| 5 mL | 1 mg/mL | 1 mg/mL | Five-fold dilution compared with 1 mL |
| 10 mL | 0.5 mg/mL | 0.5 mg/mL | Ten-fold dilution compared with 1 mL |
Use the BacScience Universal BAC Water Calculator for single-compound concentration mathematics. For a multi-component vial, enter or verify each ingredient's mass separately rather than combining all peptide masses into one concentration.
Open the Universal BAC Water Calculator →MOTS-c research includes mechanistic, animal and observational human work. Human interventional research is developing, but established clinical efficacy and safety cannot be inferred from endogenous biomarker studies.
Elamipretide has been evaluated in multiple human trials, but trial outcomes vary by indication. The negative primary outcome in MMPOWER-3 is particularly important when evaluating broad claims about mitochondrial myopathy.
Individual-component evidence cannot be converted into evidence for MOTS-c + SS-31. No controlled combination efficacy or safety conclusion should be presented without a study directly testing the combination.
Product names and commercial research formulations may vary. Always use the exact label-specific mass of each component when performing concentration mathematics.
Regulatory status must be evaluated separately for each compound. Elamipretide has an FDA-approved indication as Forzinity for improving muscle strength in eligible patients with Barth syndrome. That approval does not establish approval for MOTS-c, the MOTS-c + SS-31 combination, or general longevity applications.
MOTS-c remains an investigational research compound. The existence of an FDA substance record or a registered clinical study should not be interpreted as FDA approval.
It is a descriptive research combination containing MOTS-c and SS-31/elamipretide. It is not a universally standardized clinical formulation.
No. MOTS-c is a mitochondrial-derived peptide encoded by mitochondrial DNA, whereas SS-31/elamipretide is a synthetic mitochondria-targeted peptide associated with cardiolipin biology.
No controlled human study evaluating the complete MOTS-c + SS-31 combination was identified for this review. Evidence for either compound individually should not be presented as combination evidence.
No FDA approval for MOTS-c as a therapeutic product is established by the presence of the FDA substance record. MOTS-c remains investigational, with human clinical research developing.
Elamipretide, also known as SS-31, was granted accelerated FDA approval in 2025 as Forzinity for improving muscle strength in eligible patients with Barth syndrome. This is an indication-specific approval and does not establish approval for general mitochondrial support or the MOTS-c + SS-31 combination.
Divide the labeled MOTS-c mass by the final liquid volume. For example, 5 mg divided by 5 mL equals 1 mg/mL.
Divide the labeled SS-31 mass by the same final liquid volume. Each component needs its own calculation.
You can calculate total peptide mass, but you should not use the combined mass as the concentration of each component. A 5 mg MOTS-c + 5 mg SS-31 vial contains 10 mg total peptide, but at 5 mL each component is still 1 mg/mL.
Mathematically, yes. If component mass remains constant, increasing the final volume decreases the component's concentration.
No. A theoretical rationale for combining two mitochondrial research compounds is not equivalent to experimental evidence of synergy.
Last reviewed: September 11, 2026. Evidence and regulatory status should be rechecked periodically because MOTS-c clinical development and regulatory information may change.
| Page | Recommended anchor text | Purpose |
|---|---|---|
| Universal BAC Water Calculator | BAC water concentration calculator | Mathematical concentration calculations |
| MOTS-c Research | MOTS-c research | Individual-component evidence |
| SS-31 / Elamipretide Research | SS-31 research | Individual-component clinical evidence |
| Reading a COA | how to read a peptide COA | Identity, purity and batch documentation |
| Independent Laboratory Testing | independent peptide testing | Testing transparency and verification |